Patent GB-895233-A (GB)
Title: Improvements in or relating to weighing scales
IPC: G01G23/40
Filed: 1961-01-06
Abstract: 895,233. Weighing apparatus. FORSBERG, K. V. Jan. 6, 1961 [Jan. 9, 1960], No. 629/61. Class 143. A price computing device for weighing scales of the type including a pivotable arm comprises a movable member adapted to sense the position of the arm, price indicating mechanism including a rotatable indicating member, and adjustable travelating mechanism connecting the sensing and indicating members. A scale 4, of known construction, cooperates with an indicator 5 and coaxial with the axis of rotation of the indicatior 5 are hub sleeves 11, 12 carrying, respectively, a sensing arm 6 and a roll 7. A roll 39 and an electric selector disc 42 are rotatable on a shaft 41, the disc being biased to anti-clockwise rotation, as viewed in Fig. 1, by a spring 43. The rolls 7 and 39 are formed by the windings of a thin steel band 46, which also connects them. A pointer 50 rests, through a small roller 49, against the periphery of the roll 39, and points to a scale 52 calibrated to indicate the price per unit of weight. The face of the disc 42 has rows of embossed knobs at varying distances from its periphery and when a plate 53, and a corresponding plate behind the disc, are brought into contact with the disc, electrical connection is established from one knob, through a selector contact on the plate, to a comptometer, not shown. The hub sleeves 11, 12 are releasably coupled, Fig. 3, and when a nut 16 is screwed back the roll 7 can be rotated independently of the sensing arm 6 by a crank 15. A similar coupling, with a crank 45, is arranged between the roll 39 and the disc 42. By disconnecting the rolls 7 and 39 from the arm 6 and disc 42 and rotating them by means of the cranks, the band 46 is unwound from one roll and wound on the. other until the pointer 50 indicates a desired price per unit of weight, whereupon the couplings are reconnected. The band tension is adjustable by a set screw 48. When the pan 56 is loaded, the movement of the scale-arm 60 closes a pair of contacts 58, 59 and, after a predetermined period to allow the indicator 5 to assume its correct position (corresponding angular movement having been transmitted to the disc 42), a relay 67 closes its contacts 68, 69 and starts a motor 27. A cam 38 is thereby rotated in a direction to raise a roller 37 along a steep shoulder 57. The roller 37 is carried on a lever 36, pivoted at 35, which rises and moves a rod 33 upwards. This movement rotates. a crank 31, Fig. 3, and, through an interconnecting pin 30, a crank 32. Clamping bars 29, extending from the ends of the cranks 31, 32, are thus brought together to lock the indicator 5 in position between them. Another lever 24, pivoted at 23, is connected, through a rod 22, to an arm 20 and has a roller 25 which follows a cam 26. On rotation of this cam the lever 24 rises and a spring 21 rotates the arm 20 and with it the sensing arm 6 until the latter strikes the indicator 5. At this, contacts 18, 19 carried by the arm 6 are closed and complete a circuit which includes the coil of a magnet 55. Operation of this magnet moves the plate 53, and its associated plate, into contact with the disc 42 and current is supplied to the comptometer, in accordance with the angular position of the disc, for registering the value of the goods weighed. A relay 66 is operated at the same time as the magnet 55 and maintains the circuit of the latter when the cams 26, 38 have completed their travel and the sensing arm 6 is released and the motor circuit broken. The contacts 58, 59 are included in the circuit of the magnet 55 and this circuit, and that of the relay 66, are therefore broken when the load is removed from the pan 56. In various modifications, motors may be used instead of the cranks 15, 45; the clamping bars 29 may be operated by an electromagnet; the computer may be replaced by a dial and pointer; the pointer 51 and dial 52 may be associated with the roll 7.